conotoxin

Conotoxins are a diverse group of short peptides produced by marine cone snails (family Conidae) as part of their venom arsenal used for prey capture, defense, and competition. Each peptide is encoded by a specific gene and undergoes extensive post‑translational modifications, resulting in a high degree of structural and functional diversity. Conotoxins typically range from 10 to 40 amino acids and contain multiple disulfide bonds that stabilize their three‑dimensional conformations.

The toxins are classified into superfamilies based on their signal sequence, cysteine framework, and target specificity. Major functional groups include α‑conotoxins, which block nicotinic acetylcholine receptors; ω‑conotoxins, which inhibit voltage‑gated calcium channels; μ‑conotoxins, which block voltage‑gated sodium channels; and δ‑conotoxins, which alter the inactivation kinetics of sodium channels. This specificity makes conotoxins valuable tools for neurophysiological research and drug development.

One of the most studied conotoxins, ω‑conotoxin MVIIA (ziconotide), is approved for the treatment of severe chronic pain and acts by selectively blocking N‑type calcium channels in the spinal cord. The therapeutic potential of other conotoxins is under investigation for conditions such as epilepsy, cancer, and cardiovascular disease.

Ecologically, conotoxins enable cone snails to immobilize prey ranging from fish to worms. The evolutionary arms race between snail and prey has driven rapid diversification of conotoxin genes, making cone snail venoms one of the richest sources of bioactive peptides in nature. Research continues to uncover new conotoxin sequences, expanding both scientific understanding and biomedical applications.